Net Cages Research Articles

Monitoring the water quality of Belawan Sea for rearing asian seabass Lates calcarifer in a floating net cage system

Belawan is a coastal area located in Medan Belawan District, North Sumatra Province. The aim of the research is to determine the feasibility status of the study location if it is developed as a location for floating net cages (KJA). The research was carried out in the sea waters of Belawan in August–September 2022. The research parameters observed during the research were hydrooceanographic data and water quality data including physical parameters, chemical parameters, biological parameters. Determination of water quality status using the STORET Index, CCME WQI Index and principal component analysis (PCA). Observation parameters during the research were clinical symptoms, histological observations and growth performance of Asian sea bass. The research results show that tides, COD and turbidity are parameters that do not comply with water quality standards. The types of phytoplankton consist of 15 species and 4 classes, namely Cyanophyceae, Chlorophyceae, Bacyllariophyceae and Dynophyceae. Observation total vibrio count (TVC) shows that in all water samples it is Log 105 CFU/mL and in snapper organs (gills, liver, kidneys) there are Log 104-105 CFU/g. The results of the research can be concluded that for each zone in Belawan waters there is no difference in the level of pollution between zones in terms of the STORET index (moderately polluted) and the CCME WQI index (marginal) with limiting factors namely COD and turbidity. Belawan waters are in less than suitable condition in August–September for snapper cultivation activities in floating net cages (KJA) characterized by low SR and ADG values. Keywords: Belawan Waters, CCME WQI index, STORET index, principal component analysis (PCA), water quality monitoring ABSTRAK Belawan termasuk kawasan pesisir yang terletak di Kecamatan Medan Belawan, Provinsi Sumatera Utara. Tujuan dari penelitian adalah untuk menentukan status kelayakan lokasi kajian jika dikembangkan sebagai lokasi keramba jaring apung (KJA). Penelitian dilaksanakan di perairan laut Belawan, Kota Medan yaitu pada bulan Agustus–September 2022. Metode pengambilan sampel dilakukan secara purposive sampling. Adapun parameter penelitian yang diamati selama penelitian yaitu data hidro oseanografi dan data kualitas air meliputi parameter fisika (konduktivitas, TDS, salinitas, suhu, kecerahan, kekeruhan), parameter kimia (DO, BOD, COD, amonia, pH), parameter biologi (plankton, TVC). Penilaian kualitas perairan menggunakan Indeks STORET, Indeks CCME WQI dan principal component analysis (PCA). Parameter pengamatan saat penelitian yaitu gejala klinis, pengamatan histologi dan kinerja pertumbuhan ikan kakap putih. Hasil penelitian menunjukkan bahwa pasang surut, COD dan kekeruhan merupakan parameter yang tidak sesuai dengan baku mutu kualitas air. Adapun jenis fitoplankton terdiri dari 15 spesies dan 4 kelas yaitu Cyanophyceae, Chlorophyceae, Bacyllariophyceae dan Dynophyceae. Pengamatan total vibrio count (TVC) menunjukkan bahwa pada seluruh sampel air yaitu Log 105 CFU/mL dan pada organ ikan kakap (insang, hati, ginjal) yaitu Log 104-105 CFU/g. Hasil penelitian dapat disimpulkan bahwa setiap zona dalam perairan Belawan tergolong tercemar sedang dan tidak terdapat perbedaan tingkat pencemaran ditinjau dari indeks STORET dan indeks CCME WQI dengan faktor pembatas yaitu COD dan kekeruhan. Berdasarkan hal tersebut, Perairan Belawan dalam kondisi kurang layak untuk kegiatan budidaya ikan kakap di keramba jaring apung (KJA) ditandai dengan nilai SR dan ADG yang rendah. Kata Kunci: indeks CCME WQI, indeks STORET, monitoring kualitas air, Perairan Belawan, principal component analysis (PCA)

Assessment of Deep Learning Based Image Segmentation for Identifying Floating Net Cages from Very High-Resolution Capella Synthetic Aperture Radar (SAR) Data

Assessment of Deep Learning Based Image Segmentation for Identifying Floating Net Cages from Very High-Resolution Capella Synthetic Aperture Radar (SAR) Data

Experimental study on hydrodynamic performance of the semi-submersible vessel-shaped fish cage

Deep-sea net cages play a vital role in expanding offshore farming in modern marine fisheries. In this paper, a model-scale 1:40 tank experiment was conducted for a vessel-shaped truss-structured single-point mooring deep-sea aquaculture net cage. The study focused on the hydrodynamic characteristics, including the effect of current, wave, and net on the mooring force, heave, and pitch motion behaviors. Experimental results indicate that the mooring force increases with the current velocity, draught of the cage, and wave height, but decreases with the wave period increase. Both heave and pitch movements amplitudes increase with wave height. While heave motion amplitude initially declines and then ascends with wave periods, pitch motion shows the opposite pattern. Besides the net has an obvious damping effect on the pitch motion. These results can provide data support for the design and offshore installation of vessel-shaped truss-structured net cages in the future.

A Review of the Hydroelastic Theoretical Models of Floating Porous Nets and Floaters for Offshore Aquaculture

The present review focuses on the theoretical model developments made in floating flexible net fish cages and the floating bodies application to offshore aquaculture. A brief discussion of the essential mathematical equations related to various theoretical models of flexible net cages in the frequency domain is presented. The single and array of floating or submerged flexible net cages connected with or without mooring lines are discussed. Further, as the combined effect of the hydroelastic behaviour of floaters and the flexible behaviour of fish cages are necessary to assess their efficiency and survivability from structural damages, the issues and the knowledge gap between the recent and future models are also discussed. In conclusion, the practical suggestions concerning advancements in future research and directions within floating flexible net cages and the hydroelastic response of elastic floaters are highlighted.

Microplastic-contamination in the flesh and gastrointestinal tract of nile tilapia (Oreochromis niloticus) reared in floating net cages at lake Ranu Grati, Pasuruan, East Java, Indonesia

In recent years, microplastics (MPs) have emerged as a prominent environmental problem in waters and environments, including lake waters. Microplastics in freshwater, such as those in floating net cages (FNC), can be consumed by Nile tilapia (Oreochromis niloticus), one of the commercially available cultivated fish in Indonesia. This study aims to determine the prevalence of microplastics and compare their characteristics in the surface water, flesh, and gastrointestinal tract (GIT) of Nile Tilapia (O. niloticus) at Lake Ranu Grati, Pasuruan, East Java, Indonesia. Visual characteristics of MPs were observed using a stereo microscope, and polymers were analysed by ATR-FTIR (Attenuated Total Reflection-Fourier Transform Infrared Spectroscopy). The abundance of MPs from water sample locations in Lake Ranu Grati reached 1116 MPs particles. In the water samples, the inner and outer sides of the FNC are dominated by the MPs with a size range of 251–500 µm and 1001-2000 µm in the milieu of Ranu Grati Lake. The most common MPs' types and colours are fibre and black, dominated by Polyethylene (PE). In 25 O. niloticus samples, 576 particles of MPs were found in the flesh and 724 particles in the gastrointestinal tract (GIT). This study found no significant variation in microplastic abundance between flesh and GIT samples (p>0.05; Mann-Whitney U test). Microplastics in Nile Tilapia flesh samples were dominated by blue fibres with a size range of 101–250 µm, and the polymer found was PA (polyamide). Meanwhile, in the GIT samples, microplastics were dominated by black fibre, with a size range of 251–500 µm, and the polymer found was PA (polyamide).

Acoustic Target Strengths and Swimbladder Morphology of Chub Mackerel Scomber japonicus in the Northwest Pacific Ocean

The Northwest Pacific chub mackerel (Scomber japonicus) is one of the most productive, economically important fishery resources worldwide. Accurately assessing this species and ensuring adherence to total allowable catch limits are crucial owing to fluctuations in their abundance and distribution. Acoustic target strength measurements of S. japonicus were conducted at 38, 70, and 120 kHz using a split-beam echosounder of individuals from nine size groups (mean fork length, 10.8–28.3 cm) swimming freely in a net cage within a seawater tank. An underwater camera was utilized to simultaneously measure swimming angle. Least-squares regression analysis revealed that when the slope was constrained to 20, as per the generally applicable morphometric equation, the resulting values for the constant term (b20) were −67.7, −66.6, and −67.3 dB at 38, 70, and 120 kHz, respectively. S. japonicus mean swimming angle across the groups was −10.5–9.6° (standard deviation [SD], 16.3–33.3°). Furthermore, the ratio of swimbladder height to swimbladder length, the ratio of swimbladder length to fork length, and the tilt angle of the swimbladder (mean ± SD) were 0.191 ± 0.060, 0.245 ± 0.055, and 9.6 ± 3.0°, respectively. These results can be used for the acoustic stock assessment of S. japonicus in the Northwest Pacific Ocean.

Effect of stocking density and feeding regimes on physiological recovery in stunted Labeo rohita fingerlings reared in cages

Aim: To find out the physiological recovery status of stunted fingerling of Labeo rohita reared in floating net cages at different stocking densities and feeding rations in cages. Methodology: Stunted fingerling (8 months) of L. rohita with an average body weight of 38.23 ± 1.90 g and length 14.65 ± 0.30 cm were stocked in cages at different densities viz. T1 (10), T2 (15), T3 (20) and T4 (25) fish m-3 and varying levels of feeding rations such as 3, 4, 5 and 6% for 330 days with crude protein (28%) pellet were fed twice a day. The 4×4 factorial design was used, and each stocking density and feeding level were triplicated. A total of 48 numbers of square shaped floating net cage, made of HDPE, each measuring 27 m-3 with 6 mm mesh size were used for the experiment. Results: A significant physiological recovery was observed in the T1 (10*5 and 10*6) treatment groups, which showed highest Hb (11.23± 0.08 g d l-1), RBC (2.83 ± 0.03 ×106 cum m-1), PCV (45.76 ± 0.16 %) and lymphocyte (69.32 ± 0.12 %) content at the end of the experiment. Similarly, significant changes were observed in glucose, cortisol, and lactate dehydrogenase, which were highest in T4 and normal in T1 group as the experiment progressed. Interpretation: The result of present study recommends that cage culture of stunted Labeo rohita is possible in Indian reservoirs with lower stocking density 10 m-2 and feeding ration of 5% body weight which maintains better physiological conditions for optimal growth of fish. Key words: Cage culture, Feeding ration, Labeo rohita, Physiological parameters, Stunted, Stocking density

Insights into different marine aquaculture infrastructures from a life cycle perspective

Aquaculture facilities represent an often-neglected process in environmental impact studies. This study focus on the environmental impact assessment of alternative net materials in Mediterranean marine aquaculture. A Life Cycle Assessment was conducted using primary and secondary data from specific databases and literature. Three baseline scenarios were compared: copper alloy net cages with 100 % of recycled material (CAN100), 75 % of recycled material (CAN75), and polyethylene net (PEN) System boundaries include manufacturing and disposal of cages, nets, and mooring system. The use and emissions of antifouling paints and CAN were considered. Sensitivity analysis of the most impacting sub-processes and Uncertainty analysis were also conducted. The use of CAN is advantageous in terms of environmental impact, but only considering a complete recyclability of the net at the end of its service life. Moreover, when considering a reduced service life of the PEN due to the detrimental effect of biofouling, the advantage of the CAN is even more evident. To counteract the negative effect of biofouling, copper-based antifouling paints are generally used in marine aquaculture. These products are a main environmental hotspot in PEN systems. Therefore, a higher consumption of such products could determine an environmental burden shifting from CAN to PEN ones. So far, CAN are not widespread in the aquaculture industry, mainly due to the high cost of initial investment compared to traditional PEN. Considering operational and environmental advantages, CAN cages could represent an affordable and resilient solution for aquaculture enhancing environmental, economic, and social performances of this industry.

Numerical study on the flow characteristics of an integrated fish cage based on the monopile offshore wind turbine foundation

The integration of net cages and offshore wind turbines can effectively develop and utilize marine resources and is one of the important ways of intensive use of the sea. The numerical simulation of the hydrodynamics of an integrated fish cage based on the monopile offshore wind turbine foundation in currents is carried out. The realizable k-ε model is adopted and the porous media model is used to simulate the net. To verify the validity of the numerical model, the numerical result is compared with the data of the corresponding literature. The results show that the numerical method is effective. On this basis, the flow field distribution results of the integrated structure at different velocities are calculated. At the center of the downstream zone of the integrated structure, the time-average velocity is lower than 80 % of the initial velocity. The effects of the net solidity and the cage draught on the flow field characteristics of the integrated structure are analyzed. The results show that the increase of net solidity will significantly reduce the velocity inside the net cage and in the downstream zone of the cage. As the net solidity increases from 0.14 to 0.32, the average velocity attenuation inside the net cage increased by 13.9 %. The change of cage draught will affect the velocity distribution in the horizontal and vertical directions. When the cage draught increases, the velocity on both sides in the downstream zone of the integrated structure increases more than 5 %. It is expected that the results of this study can provide data support for the design of integrated structure of net cages and offshore wind turbines.

Experimental and numerical studies on the effect of the reinforced tubes on the drag forces of a gravity cage system

Vertical tubes are proposed to connect the collar and bottom ring to address the significant deformation of gravity cage nets caused by currents and waves. The goal is to minimize the volume loss of the cages, which reduces the habitat available for fish. This study analyses the effect of vertical tubes on drag forces using numerical and experimental methods. Tests are conducted in a towing tank to measure drag forces and validate a numerical model that employs beam and link elements to simulate the gravity cage behaviour. The differences between numerical simulations and experiments are discussed. Cages with thin tubes show larger differences than those with thick tubes due to initial bending. Comparing the results with those of gravity cages without reinforcement, it is found that the vertical tubes increase the drag force and thicker tubes exacerbate this effect. At 0.5 m/s, the cages with reinforcement tilt, leading to a different trend in drag force with wavelength compared to the cages without reinforcement.

Analysis of the relationship between primary productivity, phytoplankton abundance and nutrients in Cengklik Reservoir, Boyolali

Cengklik Reservoir is a reservoir that has many benefits for the surrounding community such as irrigation and aquaculture, namely Floating Net Cages. FNC in these waters can have an impact on the remaining feed produced in cultivation. The rest of the feed can cause increased nutrient concentrations and eutrophication in the waters. These impacts can affect water quality conditions, phytoplankton abundance and primary productivity. The purpose of this study was to determine the primary productivity, abundance of phytoplankton, nitrate (NO3) and orthophosphate (PO4) in Cengklik Reservoir, Boyolali. The study was conducted in March 2023. The sampling point determination method uses Stratified Random Sampling with four stations in two repeats. Data processing using simple and multiple linear regression analysis with Jamovi application. The results obtained gross primary productivity value is 62.50 – 156.25 mgC/m3/hour while net primary productivity is 31.25 – 93.75 mgC/m3/hour. The abundance of phytoplankton results the most in the Cyanophyceae class with a percentage of 50.72% - 65.06%. The relationship between phytoplankton abundance and gross primary productivity is obtained R2 = 0.142 while net primary productivity R2 = 0.608 which means that the relationship of phytoplankton abundance affects the production of net primary productivity in waters. The relationship between nitrate and phosphate analysis with phytoplankton abundance in waters R2 = 0.311 which means that nitrate and orthophosphate have a low influence on phytoplankton abundance. The abundance of phytoplankton in waters can be influenced by other factors.Keywords: Cyanophyceae; Nitrate; Orthofosfat; Phytoplankton

Preliminary Study on Wind Turbines for Power on Floating Net Cages

Preliminary Study on Wind Turbines for Power on Floating Net Cages

The Effect of Depth on Growth and Survival of Abalone Shells (Haliotis sp.) with A Multi-Level System

Abalone shells (Haliotis sp.), known as seven-eyed shellfish, are a type of gastropod. Abalone shells have high economic value accompanied by high market demand. The selling price of abalone reaches Rp. 250,000 (shells and meat). To optimize abalone cultivation activities with a long growth time, one method is needed for cultivating abalone shells in KJA (Floating Net Cages), namely using a tiered system in one hanger with different depths, namely 1m, 2m, 3m, 4m and 5m. so that it can increase land efficiency in cultivation activities. The aim of this research is to evaluate and analyze the effect of depth on the growth and survival rate of abalone shells (Haliotis sp.) using a multilevel system. The method used in this research was a Completely Randomized Design (CRD) experimental method with five treatments and three replications. The results of the research conducted showed that the results of the anova test on absolute length growth, specific length growth rate, absolute weight growth, specific weight growth rate, and survival of abalone shells (haliotis sp.) showed that they had no real influence (>0.05) on the maintenance of abalone shells. Based on the research results, it can be concluded that using a tiered system at different depths does not have a real effect on the growth of abalone shells because the water quality conditions at a depth of 1-5 meters are optimal so they can support the growth of abalone shells.

Hydrodynamic performance of a submersible net cage integrated with an offshore platform

The integrated development of offshore platform and net cage is a significant concern in ocean engineering. To optimize cost-effectiveness and maximize the utilization of limited ocean space resources, a composite structure is proposed, which integrates a submersible net cage onto the steel pipe piles of offshore platform. Based on the OpenFOAM software package, a numerical model is developed to assess the hydrodynamic performance of this composite structure. In this model, the net cage is simplified as a closed box structure comprising six planar nets, with each planar net further represented as a porous structure based on equivalent resistance. The model is validated by comparing the predicted results with the relevant experimental and numerical data. Subsequently, the model is employed to comprehensively investigate the hydrodynamic performance of the submersible net cage integrated with an offshore platform. Velocity variations inside and outside the net cage are analyzed under various wave-current conditions. Additionally, the forces exerted on the steel pipe piles by the net cage at different submerged depths are also examined.

Analysis of The Effect of Floating Net Cages on Reservoir Water Quality

The use of Darma Waduk is as a source of clean water and a place of fish cultivation in the form of net cages. The number of floating net cages that currently exist is 6521, and the number continues to increase quite significantly from the previous year. The existence of floating net cages affects water quality, while water quality is an aspect to be considered in water utilization. The study aims to analyze the impact of floating net cages on water quality and efforts to control the floating net cage population in Darma Waduk. The research uses a quantitative and qualitative approach, starting with surveys and interviews with floating net cage farmers and related services. Subsequently, water samples were taken, and the results of laboratory tests were analyzed using the Pollution Index (IP) method. The results of the calculation using the pollution index (IP) method at the first point (PDAM Intake Area) obtained a result of 4.14, at the second point (around the floating net cage area of the village of Cipasung) a value of 3.76, and at the third point (in the floating net cage village of Jagara) a score of 4.12. The results of the research showed that the water quality taken from the three points of the sample included light pollution when referring to the class I water quality standard according to PP No. 22 for 2021. However, the presence of household and agricultural waste also contributes to the pollution burden in the Darma Valley.

Contaminant and Assessment of Heavy Metals in Maninjau Lake, West Sumatera, Indonesia

Purpose: Water is an important fundamental resource to support human, animal and plant life. Global reports highlight widespread contamination of water sources due to various human activities. The high level of anthropogenic activity in the Lake Maninjau area, both in agriculture, animal husbandry and settlements, has an impact on decreasing the quality of the lake as indicated by the quality of the sediment and lake water. The research aims to evaluate heavy metal concentrations in sediments and heavy metal processing strategies. Theoretical Framework: Lake Maninjau is one of the lakes in Indonesia that experiences pollution. Recently, this lake has become one of the priority lakes to reduce high levels of pollution (Ministry of the Environment, 2011). The source of Lake Maninjau pollution comes from floating net cages, agriculture, settlements and livestock. This is shown by the accumulation of heavy metals in waters and sediments which is important information for the survival of fish, humans, plants, microorganisms and other aquatic ecosystems (Wibowo et al. , 2022a). Method: The five distinct sample locations were chosen to represent various activities within the Maninjau Lake region, as outlined in Figure 1 and Table 1. Sediment was taken at the surface at a depth of 0-10 cm. samples were processed and analyzed at the P3IN soil science laboratory, Andalas University, as well as assessing sediment quality through Geoaccumulation (Igeo), enrichment factor (EF), pollutant load index (PLI), contamination factor (CF), and potential ecological risk (PER) in five location of Lake Maninjau. Results and Discussion: The results of the research showed that Cu concentrations varied from 0.195 mg/kg to 0.290 mg/kg, with a moderate average of 0.246 mg/kg. Pb metal ranges between 0.325 mg/kg-0.412 mg/kg, with an average of 0.356 mg/kg. Cd metal 0.301 mg/kg- 0.365 mg/kg. The Igeo values for the metals Cr, Cd, Pb, and Cu at the five locations show Igeo < 0, meaning they are not contaminated with heavy metals. The Potential Ecological Risk Index (PER) ranges from 14.8303-19.0094, which shows the low potential ecological risk related to heavy metal pollution Research Implications: It is hoped that this research can help stakeholders in managing the Maninjau Lake ecosystem against potential heavy metal contamination that threatens the lake ecosystem Originality/Value: The use of combination or hybrid technologies to treat heavy metals from wastewater is an effective solution, but it is important to carefully consider and mitigate potential negative impacts on the environment and human health.

Stress and recovery of yellowtail kingfish (Seriola aureovittata) during Sea-land relay transportation: Biochemical, microecological and transcriptomic responses

Sea-land relay transportation (SRT) is a key part of the “land-based greenhouse + offshore net cage” mariculture system for yellowtail kingfish. In this study, the physiological status of yellowtail kingfish during SRT was assessed by determining serum biochemical indexes (levels of cortisol, glucose, and malondialdehyde (MDA), and activities of superoxide dismutase (SOD) and catalase (CAT)), the composition of intestinal microflora, and the liver transcriptome before (control), during, and after transportation (T1 and T2) and after recovery for 6 hours (6 h), 12 hours (12 h), 1 day (D1), 3 days (D3), and 7 days (D7). The results show that the serum cortisol and glucose levels, MDA level, and activities of SOD and CAT significantly increased during transportation, and decreased to similar levels to those in the control after 1 day of recovery. Bacteria including Acinetobacter, Enterobacter, and Comamonas accounted for more than 91 % of the microbial community in the gut of yellowtail kingfish, and these genera were associated with changes in serum glucose levels, indicating that they may help to alleviate the effects of transportation stress. Analyses of liver transcriptome data showed that significantly differentially expressed genes (DEGs) in the T2, D1, D3 and D7 groups were significantly enriched in the “Protein processing in the endoplasmic reticulum (ER)” pathway. At the end of transportation (T2 group), the ER-associated degradation (ERAD) pathway was activated, with up-regulation of hsp40, hsp70, and hsp90α. The transcript levels of these genes gradually returned to levels similar to those in the control during the recovery period. At the first day of recovery, the unfolded protein response imposed stress upon the ER, accompanied by significant down-regulation of PEPK and Calmin and significant up-regulation of CRT. The DEGs in the D3 group were enriched in the “ER”, “Steroid biosynthesis”, “Fatty acid degradation”, “PPAR signaling”, and “Fat digestion and absorption” pathways, whereas the number of DEGs related to lipid metabolism and stress pathways was significantly decreased in the D7 group. Our results indicate that hsp70 and hsp90α can be used as stress markers, and hsp40 can be used as a physio-metabolic recovery marker for yellowtail kingfish. These results show that, although serum indices recovered 24 hours after transportation, up to 3 days after transportation is an important period for recovery from transportation stress at the transcriptome level. “Protein processing in the ER pathway” is an important pathway regulating stress and recovery in yellowtail kingfish.

Photocatalytic mediated marine biofouling inhibition using nano CuO: TiO2-carbon dot embedded on organo silane surface modified polyethylene aquaculture cage nets

Biofouling in aquaculture cages is a potential problem and its management become major concern to the planners and farmers. The study aimed to modify the surface of polyethylene aquaculture cage nets using organo silane and to evaluate the effectiveness of a nano CuO:TiO2-carbon dot biocide treatment in inhibiting marine biofouling through photocatalytic action. Polyethylene aquaculture cage net surface modified using organo silane and the surface embedded with biocide of nano CuO:TiO2 and carbon dot (CD) derived from fish eye. The biocide-treated surface was characterized using UV–Visible and Fourier Transform Infrared spectrometry. The organo silane interacts with polyethylene via hydrogen bonding, CuO:TiO2 interacts with the silane's Si, and the carbon dots' conjugated CC bonds interact with the transition metal and silane through van der Waals electrostatic forces and hydrogen bonding. Varied concentrations of CuO:TiO2 and CD was coated sequentially over silane surface modified polyethylene, exposed in the marine environment to evaluate biofouling inhibition efficiency and found 0.05% each of CuO:TiO2 and CD was optimum. The CuO:TiO2–CD coated polyethylene cage net tested for its biofouling inhibition for 8 months in marine environment and exhibited excellent biofouling inhibition. The inhibition of biofouling was attributed to the enhanced photocatalytic action, resulting from increased electron-hole recombination, thus generating ROS, O2٠, and OH٠ radicals. This led to the highest electronic activity around the cage net and also the formation of an acidic environment deterred microorganisms. The study highlighted the use of organo silane for surface modification of polyalkenes to load the biocide and also CuO:TiO2–CD is a potential biocide for biofouling inhibition in aquaculture cages.

Effects of Innovative Cooking Techniques on the Physico-Chemical, Color, Structural and Sensory Properties of the Rainbow Trout (O. mykiss)

ABSTRACT In this study, the effects of different cooking techniques on some physicochemical, color, texture and sensory properties of rainbow trout farmed in net cage systems were investigated. The greatest water loss was found in the deep-fried group and the least water loss in sous vide group. The pH of the groups increased with cooking, but lowest pH was fish cooked sous vide. The highest L* value was determined from the group cooked under pressure of 70KPa (p < 0.05), while the lowest L* value was observed in the deep-fried group (p < 0.05). The maximum hardness (N) was found in the group cooked under pressure of 10KPa (p < 0.05). Pressure cooking techniques in automatic cookers for cooking trout cubes can be said to be one of the most suitable innovative cooking methods when color, textural characteristics and sensory juiciness values are taken into account in meat texture.

The influence of simulated pressure changes on the behavior of Larimichthys crocea during the deep sea submarine descent of net cages

The influence of simulated pressure changes on the behavior of Larimichthys crocea during the deep sea submarine descent of net cages